Electromagnetic casting systems including furnaces and molds for producing silicon tubes

A mold for forming a tubular-shaped silicon ingot, the mold comprising:

• an outer crucible, wherein the outer crucible is annular-shaped;
• and
• an inner crucible disposed in the outer crucible, such that the outer crucible surrounds the inner crucible, wherein a gap exists between the outer crucible and the inner crucible, wherein the outer crucible and the inner crucible are configured to receive granular silicon in the gap,
• wherein the inner crucible comprises a plurality of plates, wherein the plurality of plates comprise inner surfaces, sides, and outer surfaces, wherein the inner surfaces face each other and are disposed along an inner circular perimeter, wherein the plurality of plates are disposed to provide a tubular-shaped structure and are disconnected distinct plates that are able to move relative to each other, and
• wherein the plurality of plates are disposed, such that the plurality of plates are not spaced apart at a top of the tubular-shaped structure and are spaced apart at a bottom of the tubular-shaped structure such that gaps exist between adjacent ones of the plurality of plates at the bottom of the tubular-shaped structure for displacement of the plurality of plates radially inward while experiencing contraction forces of the tubular-shaped silicon ingot on the outer surfaces during solidification of the tubular-shaped silicon ingot.